Certain nitrogen-fluorine compounds and methods of preparation

ABSTRACT

1. A COMPOUND HAVING A STRUCTURAL FORMULA   (F2N-)3-C-NH-L   WHERE L IS SELECTED FROM THE GROUP CONSISTIN OF   -COO-R1, -CO-NH-R2-CO-N(-R3)-R4,   -CO-NH-NH-CO-NH-C(-NF2)3, -CO-NH2   -CO-NH-C(-NF2)3, -COO-CH2-CH2-OOC-NH-C(-NF2)3   WHEREIN R1, R2, R3, AND R4 ARE EACH INDEPENDENTLY SELECTED FROM THE GROUPS CONSISTING OF LOWER ALKYL, DIFLUOROAMINO SUBSTITUTED LOWER ALKYL, AND ARYL GROUPS. 2. THE PROCESS WHICH COMPRISES (1) REACTING A REAGENT SELECTED FROM THE GROUP CONSISTING OF   Z-NF-C(=NF)-X AND NC-NF-Y   WHEREIN -X IS SELECTED FROM THE GROUP CONSISTING OF   -F, -NF3, -NF-C(=NF)-NF2, -NF-CF(-NF2)-NF3, -NF-CN, AND   -NF-CO-NF2   WHEN Z-IS F- AND WHEREIN -X IS NF-C=N WHEN Z- IS N=C AND WHEREIN -Y IS SELECTED FROM THE GROUP CONSISTING OF -F, -C(=N-F)-NF3, AND -C(=N-F)-NF-C*N WITH AN ADDITVE SELECTED FROM THE GROUP CONSISTING OF HNCO, HNCS, AND H2NC=N TO PRODUCE AN ADDUCT, AND (2) REACTING SAID ADDUCT WIH A COMPOUND SELECTED FROM THE GROUP CONSISTING OF A LOWER ALKYL ALCOHOL, AN ALKYLENE GLYCOL, GLYCEROL, PENTAERTHRITOL, PHENOL, POLYVINYL ALCOHOL, NITROCELLULOSE, AND DIFLUORAMINOMETHANOL.

United States Patent Office 3,699,094 Patented Oct. 17, 1972 3 699 094CERTAIN NITROGEfil-FiUORINE COMPOUNDS AND METHODS OF PREPARATION WilliamCharles Firth, Jr., Wilton, and Simon Frank, Stamford, Conn., assignorsto American Cyanamid Company, Stamford, Conn.

No Drawing. Original application May 9, 1963, Ser. No. 280,492. Dividedand this application Oct. 22, 1965, Ser. No. 505,308

Int. Cl. C08b 5/04; C07c 87/22, 103/10 US. Cl. 260221 4 Claims Thisapplication is a division of our copending application, Ser. No.280,492, filed May 9, 1963.

This invention relates to a novel class of chemical compounds as well asto the methods of preparing the same. More particularly, the presentinvention is concerned with highly fluorinated aminomethyl compounds andhow such compounds are prepared.

It is well known that fluorine is a potent oxidizer for rocket fuels.However, fluorine is a gas having an extremely low boiling point makingthe use of fluorine for rocket propulsion dependent upon the maintenanceof cryogenic conditions.

In order to overcome some of the disadvantages of the use of fluorine,considerable research effort has been devoted to attempting to producecompounds containing a high percentage of available fluorine. In thecourse of such research it was discovered that fluorine bonded to carbonwas not readily avaliable for oxidation of fuels while fluorine bondedto nitrogen was readily avaliable. Accordingly, our research has beendirected toward producing compounds having a high percentage of fluorineattached to nitrogen.

Prior research into the preparation of oxidizers having a highpercentage of available fluorine, such as ClF BrFtris(difluoramino)fluoromethane and FClO had reached a limit in theprogress of technology where the best that could be hoped for fromtheoretical considerations was a minor improvement in the specificimpulse of fuel-oxidizer combinations based on extensive minormodifications of the proportions of fuel to oxidizer, hardware design,etc. In order to make a major improvement in the specific impulse ofthese fuel-oxidizer combinations, new compounds having a much higherpercentage of available fluorine were needed. Quite unexpectedly andwithout any benefits of prior knowledge in this field we discovered aunique method of producing a highly valuable and heretofore unknownclass of fluorine compounds.

Accordingly, an object of this invention is to provide a unique methodof producing novel fluorine compounds.

Another object of this invention is to provide a unique group offluorine compounds.

Other objects and advantages of this invention will become apparent fromthe following description and explanation thereof.

In a preferred aspect, the present invention is concerned with thereaction between 1) a compound in which a central carbon atom ismultiply bonded to a nitrogen atom and also singly bonded to anadditional nitrogen atom and (2) an acidic nitrogen-containing compoundor reagent having active hydrogen to produce an addition product oradduct in which the nitrogen atom of the reagent adds or couples to theaforesaid central carbon atom.

The preferred starting compound in which a central carbon atom isattached by multiple and single bonds to separate nitrogen atoms may berepresented by the following structural formula:

wherein X, is hydrogen or fluorine, X and X are the same or separatesubstituents such as fluorine, cyano, etc.;

II. F NF I 1] a d Z1N X III. NEC-NFY1 wherein X is selected from thegroup consisting of NF NF:

when Z is fluorine, wherein X is NFCEN when Z is a cyano group, andwherein Y is selected from the group consisting of The starting fluorinecompound described above is pref erably reacted with anitrogen-containing acid which has active hydrogen, and may berepresented by the formula:

IV. HR

wherein R is a radical selected from -N=C=O, -N=C=S and -NHCEN.

The reaction between the fluorine-containing compound or reactant andthe acidic reagent is an addition reaction and the results in anaddition product or adduct, which to the best of our knowledge has neverbeen produced before. The adduct may be represented by the followingformulae:

wherein R, X Y and Z include the radicals or substituents given in thedescriptions of R, X Y and Z in Formulae II-IV, inclusive, hereinabove.The substituents X Y and Z include additional substituents for thereason that additional central carbons may be combined with the acidicreagent to similarly reduce the degree of unsaturation present therein.Further, the cyanamide compound has two active hydrogens, and thereforeit can serve to saturate the multiple bonds in two dilferent reagentmolecules. Still further, where the fluorine-containing startingcompound contains a plurality of central carbons and the acidic reagentcontains a plurality of active hydrogens, complex adducts may beproduced wherein the acidic reagent serves as a bridge between a pair offluorine-containing compound molecules and the fluorine-containingcompound can combine with a pair of such acidic reagent molecules. Thus,relatively large adduct molecules may be built up in this circumstance.

Accordingly, in Formulae V-VII inclusive, X and Y may include themoieties described in Formulae II- IV, as well as the following:

X may include wherein R is the same as R previously defined when Z isfluorine and Y may also include NHF NHF |JNF; and JJNFCEN wherein R isthe same as R previously defined.

It is also contemplated within the scope of the present invention tosubject the adducts represented by Formulae V-VII inclusive tofluorinolysis to produce novel highly fluorinated products. The novelhighly fluorinated products or adducts of importance may be representedby the following formula:

VIII. N F:

wherein Q is a nitrogen-containing moiety selected from the groupconsisting of -NCO, NCS, NFCEN, NF NHCF=NF, --NFCF=NF, --NFCF NF andNFCF and wherein G is selected from the group consisting of fluorine,

wherein Q, is the same as Q. Thus, it is the unusual characteristic ofthese novel highly fluorinated products that they contain a carbontetranitrogen nucleus with large amounts of readily available fluorineattached to the nitrogens therein.

Among the most outstanding compounds thus produced are: C(NF M ortetrakis(difluoramino)methane and (F N) CNC0 or tris(difluoramino)methylisocyanate. These compounds have never been made before, and judgingfrom past knowledge it would appear not possible to produce them.

The novel compounds of the present invention have many uses,particularly for those applications in which highly available fluorinecontent is desirable. The novel compounds may be used as oxidizers forthe oxidation of rocket fuels of the liquid, hybrid, and solid types,explosives, and smoke generators, intermediates for the production ofother fluorine-containing compounds, insecticides, herbicides, etc.

With respect to the use of the adducts as intermediates, it should benoted that they are highly fluorinated compounds containing reactivesites in the form of nitrogen to carbon unsaturations. For example,where the adduct contains a cyano group or a thiocyano group, it may bereacted with alcohols, carboxylic acids, amines, oxidizers, andhydrolysers. The nature of the reaction is similar for all the adductsof the present invention, and is exemplified by the following equations:

wherein Z and X have the meanings given in Equation V, above, X isoxygen or sulfur and R OH represents a lower alkyl alcohol, a glycol, aglycerol, pentaerythritol, phenol, polyvinyl alcohol, nitrocellulose,difluoraminomethanol, etc.

wherein Y has the meaning given in Equation VI and X and R OH are thesame as in Equation IX.

XIIa. X1 a -N=C=X1 R NHR1 -NH--gI I-R1 wherein R and R are alkyl groups.

In the hydrolysis of each of the adducts given in Equations IX-XIinclusive, the cyanate or thiocyanate radical is combined with water inthe following manner:

XIII. N=C=X +HOH NH +COX Under certain conditions, the amine produced inEquation XIII may additionally react with a cyanate or thiocyanateradical as follows:

XIIIa. X1

x ('5 Ali,

g H 1 H In a similar manner, those adducts containing a nitrile groupmay be reacted with hydrolyzers, alcohols, and amines. The nature of thereactions is similar for all the adducts of the present invention, andis exemplified by the following equations:

wherein M and M are the same or different substituents such as (Z X Y Rhave the meanings given in Equations V, VI, and VII above) and wherein Mmay also be H. The above reaction in Equation XV may also proceedfurther under stronger hydrolyzing conditions as follows:

XVI. M1 M1 l t-i j-Nm H2O 1 111 C0, NH; Iii, it.

M and M have the meanings given in Equation XV.

When treating the adduct with an alcohol having the formula R 'OHwherein R OH may have the same meaning as R OH given in Equation IX,above, the following reaction occurs:

wherein M and M have the same meanings as M and M respectively, given inEquation XV.

When using an amine having the formula a Rvl lfl wherein a R7IIH may bea primary or secondary lower alkyl amine, an

aromatic amine, hydrazine, monoor di-substituted hydrazine, a urea,hydroxylamine, an amide, nitramine, a

mono-substituted nitramine, an imide, the following reaction occurs:

wherein M and M have the same meanings as M and M respectively.

The products produced according to Equations IX 6 through XVIIII,inclusive have relatively high NF to C ratios making them useful asoxidizers in rocket propellants and explosives. Additionally, since manyof these products have relatively higher molecular weights, they haverelatively lower vapor pressures (high-boiling liquids or solids) makingthem extremely useful as oxidizers or plasticizers. To further increasethe NF to C ratios, these compounds may be subjected to mildfluorinolysis to replace the remaining hydrogens with fluorines, asfollows:

wherein the molecule on the left side of Equation XIX is the same asproduct on the right side of Equation 1X.

wherein the molecule on the left side of Equation XX is the same as theproduct on the right side of Equation X.

wherein the molecule on the left side of Equation XXa is the same as theproduct on the right side of Equation XX, illustrating further mildfluorinolysis thereof.

wherein the molecule on the left side of Equation XXI is the same as theproduct on the right side of Equation XI.

XXII.

wherein the moiety on the left side of Equation XXII is the same as theone produced on the right side of Equation XII.

XXIII.

wherein the moiety on the left side of Equation XXIII is the same as theone produced on the right side of Equation XIII.

XIV. X R5 5 wherein the moiety on the left side of Equation XXIV is thesame as produced on the right side of Equation XIVa.

wherein the molecule on the left side of Equation XXV is the same as theproduct on the right side of Equation XV.

wherein the molecule on the left side of Equation XXVI is one of theproducts shown on the right side of Equation XVI.

XXVII. M; on. M;

N- =N H F2 N- Mi Mi wherein the molecule on the left side of EquationXXVII is the same as the one shown on the right side of Equation XVII.

wherein the molecule on the left side of Equation XXVIIa is the same asthe product on the right side of Equation XXVII, illustrating furthermild fluorinolysis thereof.

wherein the molecule on the left side of Equation XXVIII is the same asthe one shown on the right side of Equation XVIII.

wherein the molecule on the left side of Equation XXVIIIa is the same asthe product on the right side of Equation XXVIII, illustrating furthermild fiuorinolysis thereof.

In addition to the replacements of H by F shown in Equations XIX toXXVIIIa, inclusive, the corresponding conversion of The foregoing highlyfluorinated reactants of Formulae II and III may generally be preparedby aqueous fluorination or fluid-bed fluorination of appropriatehydrogencontaining compounds. Frequently, these fluorinations produce aplurality of products which may be separated by fractionalcodistillation to obtain the desired reactant- Aqueous fluorinationinvolves bubbling a fluorine-containing gas through an aqueousdispersion of the appropriate hydrogen-containing compound. Fluid-bedfluorination involves contacting a fluidized bed of particulatehydrogencontaining compound with a fluorine-containing gas. Thus,

difiuorocyanamide may be prepared by aqueous fluorination of cyanamide.Also, difluoroeyanamide, perfiuoroformamidine, and perfluoroguanidinemay be prepared by fluid-bed fluorination of biguanide and isolation ofthe desired reactant from the mixture produced.

It will be noted that central carbons of two types are represented inthe starting fluorine compounds listed above, (a) carbons which aredoubly bound to a fluorinecontaining nitrogen and singly bound to anadditional fluorine-containing nitrogen and (b) carbons which are triplybound to a nitrogen and singly bound to a fluorine-containing nitrogen.It is also to be noted that any given molecule may have only a singlecentral carbon or may have a plurality of central carbons which are thesame type or of different types.

The addition reaction to produce the adduct of Formulae V-VII iseffected by means of a nitrogen-containing acid which is preferablycyanic, thiocyanic or cyanamide. Each acid has an active hydrogen and iscapable of coupling with the central carbon atom of thefluorinecontaining starting compound to produce a carbon-nitrogen bondtherewith. The acid is employed in stoichiometric amounts to produce thedesired adduct, or if desired, a deficiency of acid may be used for thereaction. About 0.5 to 1.0 equivalent of acid, based on the startingfluorine compound, may be used.

The addition reaction to produce the adduct of Formulae V-VII is alsopreferably conducted in the presence of an alkaline or basic catalyst.In this connection any base or alkaline material is useful, with varyingdegrees of success. The alkaline or basic catalyst may be sodiumhydroxide, ammonium hydroxide, lithium carbonate, sodium carbonate,potassium bicarbonate, pyridine, quinoline, trimethylamine,dimethylaniline, tributylphosphine, triphenylphosphine, substitutedammonium compounds such as the quaternary ammonium compounds, urea,potassium cyanate, sodium cyanate, etc. We have also discovered that awhite solid material which is produced as a by-product in the additionreaction to produce adduct may also serve as a catalyst. This whitesolid material is believed to contain along with cyanic acid polymer.

The catalyst may be used for the reaction in an amount of about 0.01% to10.0%, more usually about 0.1% to 0.5% based on the weight of thestarting fluorine compound.

In producing the adduct of Formulae V-VII, a solvent may also beemployed to provide intimate or uniform distribution of the reactantsthroughout the reaction mass and to dissipate the heat of reaction, andthus serve as a means of controlling the reaction. The solvents whichcan be used are, for example, pyridine, alkyl pyridines, liquid sulfurdioxide, sulfolane, the aliphatic ethers, e.g., methyl ether, ethylether, dioxane, tetrahydrofurane; the halocarbons such astrifluorochloromethane, carbon tetrachloride, trichlorotrifiuoroethane;ketones, such as acetone, ethylmethylketone; esters, such as ethylacetate. The solvent, when used, is used in an amount such that thestarting fluorine compound and nitrogen-containing acid comprise about5% to about and preferably about 20% to about 40% of the overallmixture.

The reaction to form the adduct of Formulae V-VII may be run over a widerange of temperatures, although generally a temperature of about -78 C.to C., more usually about -35 C. to +35 C. may be used. The reaction isperformed in the liquid phase, and accordingly for such a system it ispreferred to employ a temperature of about -15 C. to +25 C. The pressureunder which the reaction is conducted may also vary considerably from asubatmospheric pressure to superatmospheric pressure. Usually thereaction is performed between about 100 mm. Hg and about 760 mm. Hg. Thereaction may proceed for from about 1 to about 48 hours but generallyrequires about 2 to 3 hours.

It is preferred to perform the addition reaction to form the adduct ofFormulae V-VII under an inert atmosphere using such gases as nitrogen,carbon dioxide, helium, argon, and low molecular weight halocarbons.

It is generally preferred to use approximately stoichiometricproportions of the fluorine-containing compounds and thenitrogen-containing acid in proucing the adduct, but one can use otherproportions as may be desired.

Illustrative of the adducts of Formulae V-VII are the followingcompounds:

The adducts of Formulae V-VII thus produced may next be fluorinated tofurther increase the content of readily available fluorine contained inthe molecule. Depending upon conditions this fluorinolysis may proceedby several mechanisms. The reaction conditions may, for the purpose ofthis discussion, be divided into mild conditions and drastic conditions.

The fluorination conditions to produce fluorinated adducts of FormulaeVIII and XIX to XXVIII may involve generally a concentration of fluorinein the gas of about 4% to 100% by volume. The reaction may be conductedat a temperature of about 50 C. to about +100 C. and at a pressure ofabout 100 mm. Hg to about 5 atmospheres. The reaction may beinstantaneous or take a time up to about 12 hours. The mild reactionconditions generally involve the lower ends of the foregoing ranges andthe drastic conditions generally involve the upper ends of the foregoingranges. Thus, mild monditions generally involve a concentration offluorine of about 4% to about 20% by volume with a temperature of about-50 C. to about 0 C. at a pressure of about mm. Hg to atmospheric for atime shorter than about a half a minute. Drastic conditions generallyinvolve high fluorine concentration in the gas of more than about 20% byvolume with the reaction temperature about 0 C. to about 100 C. [at areaction pressure from about atmospheric to about 5 atmospheres and aresidence time from about half a minute up to about 5 hours.

It is to be understood that all of the drastic conditions do notnecessarily have to be present for the reaction conditions to beconsidered drastic nor do all of the mild conditions have to be presentfor the reaction conditions to be considered mild. Whether the reactionconditions are to be considered mild or drastic depends upon the netbalance achieved by the interaction of all of the conditions involved.

Fluorination of the adduct using either mild or drastic conditionsserves to replace the hydrogen introduced onto nitrogen formerlymultiple bound to the central carbon with a fluorine so that the -NHF,=NH, or NH group becomes an NF or =NF group.

Mild fluorination conditions also preferentially serve to add F to anyunsaturations present in the adduct, that is by reducing theunsaturation still remaining therein. Thus, for example, whereperfluorobiguanide is reacted with cyanic acid to saturate one centralcarbon leaving the other central carbon with a doubly bound nitrogenafiixed thereto, addition of fluorine under mild conditions would tendto add one atom to the remaining =NF group and one atom to the group toproduce Under drastic conditions, the reaction of the fluorine with theadduct may serve to cleave bonds between the carbon and the groupsafiixed thereto or bonds between nitrogen and the groups aflixed theretoand replace them with C-F or N--F bonds.

Another possible reaction under drastic conditions is the cleavage ofbonds within the groups attached to the central carbon. For example,N=C,=O may be converted to -NF by such drastic reaction conditions.

The reaction may result in a mixture of all four types of reactionproducts, with the drastic reaction conditions tending to give a greaterproportion in the product of the cleavage reactions and the mildconditions tending to give a higher proportion of the addition reaction.

Illustrative of the products of such fluorination of the adducts withinthe scope of Formula VIH are the following:

Adducts, as well as mildly fiuorinated adducts, may further be reactedwith materials containing active hydrogens. Illustrative of such activehydrogen compounds are H O, R OH, R NH RsNHRq, and R COOH (also R OH andR NHR as defined in Equation IX through XVIII, inclusive.

The active hydrogen compound may be employed in stoichiometric amountsin the reactions of Equations IX through XVIII, inclusive, or ifdesired, an excess or deficiency of active hydrogen compound may be usedfor the reaction. About 0.5 to 20.0 equivalents, and, preferably 0.9 to2.1 equivalents of active hydrogen compound, based on the adduct, may beused. Frequently, this reaction will occur upon admixture of the tworeactants alone or in an inert diluent, such as ether. In other cases,the presence of a catalyst is helpful. Such catalysts in clude basiccatalysts, such as tertiary amines (e.g., triethylamine,triethylenediamine), acid catalysts, and metallic compounds, especiallytin compounds, such as dibutyltin laurate, dimethyltin dichloride,tributyltin acetate, stannic chloride, etc.

These reactions may be conducted at a temperature of from about 50" C.to about +100 C., more usually from C. to +35 C., and still moreparticularly from +5 C. to C., and at a pressure of from about 100 mm.Hg to about 5 atmospheres, and more usually at about 1 atmosphere. Wherecatalysts are used, they generally are used at a concentration of 0.01%to 10.0% and more usually at a concentration of 0.1% to 1.0%, based onthe weight of the other reactants.

Illustrative of the products of reacting such adducts with activehydrogen compounds as defined in Equations IX through XVIII are:

In any of the foregoing reactions wherein a mixture of products isproduced, such mixture may be separated into its component parts byconventional techniques, such as gas chromatography, fractionaldistillation, fractional codistillation, liquid-solid chromatography,fractional crystallization, etc., or by a sequence of a plurality ofsuch techniques.

EXAMPLE 1 The following example illustrates the preparation of somestarting materials (difluorocyanamide, perfluoroformamidine, andperfiuoroguanidine) by fluid-bed fluorination of biguanide.

Five grams of biguanideadmixed with 26.8 grams of sodium fluoride (bothhaving approximately the same particle sizes, e.g., from about 80 toabout 200 mesh) are placed in a fluid-bed reactor and fluidized bypassing therethrough a carrier gas (4% F and 96 He by volume) at atemperature of C. for 4 hours. The product collected at '196 C. from thefluorination of the biguanide is stored as a gas in 9 bulbs, each about450 ml. in volume. Difluorocyanamide is isolated from the crude productfractions by fractional codistillation technique [Anal. Chem., 31, 618(1959)]. Difluorocyanamide is then passed through the fractionalcodistillation apparatus a second time to tyield a total of 7 mmoles ofpurified difluorocyanamide.

Similarly, using 2.5 grams of biguanide admixed with 25 grams of sodiumfluoride and reacting for 2 hours at 2 C. with the carrier gas in thefashion indicated above, 22 mmoles of volatiles are collected.Fractional codistillation permits separation into 27%perfluoroformamidine, 18% perfluoroguanidine, and 8% difluorocyanamide.

EXAMPLE 2 The following example illustrates the preparation of astarting material (difluorocyanamide) by aqueous fluorination.

To a 300 ml. round-bottomed flask having a 24/40 ST joint is added 46ml. (44 g.) of a 50% aqueous cyanamide solution. To this solution isadded an aqueous slurry (buffering agent) prepared in the followingmanner:

Seventeen (17) g. NaH PO -H O mixed with 45 g. Na HPO -12H O is slurriedwith 5 ml. of water. Some of this phosphate slurry dissolves in thecyanamide solution but most of it settles to the bottom of the flask.

The flask is fitted with an inlet tube extending ap proximately 3 cm.below the surface of the liquid, the pH of which is 5.6. An exit tubepositioned above the liquid surface and extending out of the flask leadsdown- 13 stream to four cold traps (two at 78 C. and two at 196 C.) forisolation of the volatile fluorination products.

The 300 ml. flask is surrounded by a large beaker of Water at about 9 C.A stream of helium is started 14 nate which may be characterized byinfra-red spectra, gas chromatography, molecular weight determinations,etc.

EXAMPLE 5 In a similar manner perfiuorobiguanide is reacted with bubbhngthrough. the Solutlon h k i a of two equivalents of cyanic acidutilizing KOCN as the about 700 E F2 ls.mlxed thefhebmm catalyst. Amixture of products is produced wherein one Stream i h ter g 3-4 q i a0W 9 aflout and both G N groups are saturated by the cyanic acid. 40mL/mm' atiame ehum and flllonne 3 These products may also becharacterized by infra-red rates are mamtamed thrpug out react1n.pen9 10spectra, gas chromatography, molecular weight determi- The water bathsurroundlng the reaction flask mainnations etc o o tamed between 9 C.and 12 C. by addmg small amounts EXAMPLE 6 of ice. After 55 minutes thesolution (pH of 4.9) becomes dark red-orange in color and the flow of Fis stopped. The following example illustrates the fluorination ofIsolation of the product retained in the two cold traps 15bis(diflllofamino)flllofamillomethyl isocyanate to P at 196 C, bvacuumqine technique (b lb-t -b lb duce tetrakis(diflu0ramino)methaneand tris(difluordistillation) yields mmoles of product. Infraredanaminomethyl i y n alysis indicates that the composition of the productis BiS(difiu01'amiI10)fll101'amin0m6thY1 isocyanate was approximately70% DEC and 30% CO Traces of other fluorinated y Sweeping afluorine-helium gas mixture products amount to 1% or less of the totalproduct. From 20 for an extended Period of time at low temperatures CV61a bulb containing 7.5 mmoles of the crude product i ob- Such material.Entrained in the exiting fluorine-helium tained 5.4 mmoles of puredifluorocyanamide. gas mixture were the reaction products,tetrakis(difluor- EXAMPLE 3 amino)methane and tr1s(d1fluoram1no)methylsocyanate along with assorted by-products as shown 1n the The followingexample illustrates the reaction of accompanying table.perfluoroguanidine with cyanic acid to produce bis(di- These productswere collected by passing the exiting fluoramino)clluoraminomethylisocyanate. fluorine-helium gas mixture containing the products Equalmolar amounts (1.5 mmoles) each of perfiuorothrough an HF trap (aU-shaped tube which is filled with guanidine and cyanic acid werecondensed at -l96 sodium fluoride pellets), then through a first coldtrap C. into a flamed 1.3 ml. nuclear magnetic resonance tube (aU-shaped tube chilled to 78 C. or --196 C.) and equipped with aFisher-Porter needle valve and conthen into a second cold trapmaintained at 196 C. taining powdered urea as a catalyst (0.15 mmole orNon-condensables at -19'6 C. were passed out through 0.0090 gram). Thereaction was allowed to proceed at a bubbler.

TABLE Fluorlnation conditions Products He, F2, Temp., Duration, Tris,Yield, Delta, Yield, Others, cc./min. cc./min. 0. minutes Other mmolepercent mmole percent mmole 350 10 -30 60 NoteA 0.16 23 .084 12 1 0.49350 10 -30 60 do... 0.20 18 0.16 14 1 0.48 350 10 a0 140 ...do 0.62 280.48 22 1 1.0 350 10 30 120 --do 0.41 26 0. 28 1.2 350 10 -30 90+80 NoteB 0.2 10 1.0 43 2.5

I SiF4, N02 and unknowns. Note A=HF trap filled with NaF pellets and at25 0.

Note B=Fluo1ination as for Runs 1-4 except that adduct was fluorlnatedin two portions and products combined.Norm-Bis=bis(difiuoramino)fluoraminomethyl isocyanate; T1is=tris(difluoramino)methyl isocyanate; Delta=tetrakis(dlfluoramino)methane.

about 30 C. (produced by a magnesium chloride-ice mixture) for about 3hours followed by about 1 hour at room temperature (about 25 C.).

All products which were volatile at room temperature were isolated bytransfer on a vacuum line into a condensing bulb cooled to -196 C. Thisbulb was then allowed to warm up to room temperature which thenpermitted vapors to pass from this bulb into a trap cooled to C. (by acalcium chloride-ice mixture) and from this trap into another condensingbulb cooled to 196 C. The material volatile at -50 C. consisted of smallamounts of unreacted perfluoroguanidine and cyanic acid while thematerial condensed in the 50 C. trap consisted only ofbis(difluoramino)fiuoraminomethyl isocyanate. The yield ofbis(difiuoramino)fiuoraminomethyl isocyanate was about 54%.

EXAMPLE 4 The following example illustrates the reaction betweenperfluoroformamidine and cyanic acid to producedifiuoramino(fiuoramino)fluoromethyl isocyanate.

0.116 gram of perfluoroformamidine and 0.43 gram of cyanic acid areintroduced on a vacuum line into a 10 cc. evacuated bulb containing0.010 gram of urea as a catalyst. The reaction is allowed to proceed forabout 3 to 5 hours at 30 C. followed by about 1 to 2 hours at roomtemperature. After pumping oif any volatile materials, the less volatileresidue is distilled under vacuum at room temperature into a coldreceiver. The distillate thus produced and collected in the receiver isdifluoramino(fluoramino)fluoromethyl isocya- EXAMPLE 7 The followingexamples illustrates the reaction of tris (difluoramino)methylisocyanate with methanol to produce a carbamate.

A Pyrex nuclear magnetic resonance tube of approximately 1.3 ml. volumewas used as a reactor for this reaction. This reactor could be openedand closed by means of a Teflon needle valve, and could be connected toa vacuum line by means of a ground-glass connection.

Ten microliters (0.25 mmole) of reagent grade methanol was added from amicroliter syringe to a dry reactor as described above. The reactor wasthen cooled in liquid nitrogen and evacuated, and 0.28 mmole of tris(difluoramino)methyl isocyanate was condensed therein. The reaction wasallowed to proceed for minutes at 0 C. and then for 10 minutesadditional at room temperature. A small amount of volatile material wascondensed out of the reactor. The residual liquid was methylN-tris(difluoramino)methylcarbamate according to infrared and nuclearmagnetic resonance (H' and F analyses. However, the H nuclear magneticresonance analysis indicated that the product was not completely pure.Upon purification, this carbamate is a solid with a melting point of4344 C. Calculated for C H F O 47.09% F. Found 47.70% F.

EXAMPLE 8 The following example illustrates the reaction of tris(difluoramino)methyl isocyanate with ammonia to produce a urea.

A dry reactor (as described in Example 7) was charged with about 0.3 ml.of anhydrous ethyl ether and degassed at 196 C. Tris(difluoramino)methylisocyanate (0.2 mmole) was condensed into the ractor and allowed todissolve into the ether when the reactor was warmed to room temperature.Then 0.2 mmole of anhydrous ammonia was condensed into the tube at 196"C. This reaction mixture was then warmed to room temperature in 10minutes and allowed to remain at room temperautre for an additional 20minutes. The volatiles were removed from the resulting solution leavinga white oxidizing solid residue, whoe infrared spectrum indicated thepresence of tris(difluoramino)methylurea, a solid which could be vacuumsublimed.

EXAMPLE 9 The following example illustrates the hydrolysis oftris(difiuoramino) methyl isocyanate to produce an amine.

A dry reactor (as described in Example 7) was charged with 0.7 mmole ofwater, cooled to about 196 C. and evacuated. After condensing 0.7 mmoleof tris(difluoramino)methyl isocyanate into the reactor, it waspermitted to warm up to room temperature. After allowing the reaction toproceed for 17 hours at about 25 C., the volatiles were fractionated inthe vacuum line using a trap cooled to about 80 C. by a Dry Iceacetonebath. The gas passing through the trap was largely carbon dioxide. Thetrap contained 0.5 mmole of tris(difluoramino)methylamine, a novelcompound identified by its infrared spectrum and F and H nuclearmagnetic resonance analyses.

The various products produced by the fluorination of the adducts aregenerally useful as oxidizers in conjunction with fuels for rocketpropulsion. This is because they contain a large proportion of readilyavailable fluorine (attached to nitrogen) for such oxidation reactions.

Also, these adducts and final products may serve as intermediates forthe preparation of other compounds by reaction of the isocyanate portionor the C=N or CEN portions with oxidizers, alcohols, amines, hydrationagents, etc., to form other highly fluorinated aminomethyl compounds. Asillustrative of the use of one of these compounds,tetrakis(difluoramino)methane, as an oxidizer for rocket propellants,the following data is presented:

sp 2) r+ z 4-i- 2 4 329 C(NF2)4+N2H4+FC103 322 C(NF +(CH NNH +N O 320C(NF +B Hg+N 329 I is the theoretical specific impulse to be obtained bycalculations utilizing the optimum proportions of the three ingredientspresented.

In contradistriction to the above, the following data was obtained forpreviously known oxidizers:

so ClF +N H 29s FC(NF2)3+N2O4+N2H4 314 FC(NF +N H +FCl0 314 ClF +B H 290FC(NF2)3+FCIO3+B5HQ 314 We claim:

1. A compound having a structural formula FaN(|3-NHL NF:

where L is selected from the group consisting of wherein R R R and R areeach independently selected from the group consisting of lower alkyl,difluoroamino substituted lower alkyl, and aryl groups.

2. The process which comprises (1) reacting a reagent selected from thegroup consisting of F NF I 4J I Z-N X and N=O-N-Y wherein X is selectedfrom the group consisting of NF NF:

o NF-PL-N Fa when Z-- is F and wherein X is NF-CEN when Z-- is NEC- andwherein Y is selected from the group consisting of NF NF F, -NFz, and fJ-NF-C5N with an additive selected from the group consisting of HNCO,HNCS, and HZNCEN to produce an adduct, and (2) reacting said adduct witha compound selected from the group consisting of a lower alkyl alcohol,an alkylene glycol, glycerol, pentaerythritol, phenol, polyvinylalcohol, nitrocellulose, and difiuoraminomethanol.

3. The process which comprises (1) reacting a reagent selected from thegroup consisting of Z-N-L-X and NEG-N-Y wherein X is selected from thegroup consisting of when Z is F- and wherein X is NF-CEN when Z- is NECand wherein Y is selected from the group consisting of with an additiveselected from the group consisting of HNCO, HNCS, and HZNCEN to producean adduct, and (2) reacting said adduct with a compound selected fromthe group consisting of ammonia, a lower alkylamine, a secondary lowerdialkylamine, an aromatic amine, hydrazine, monoand di-substitutedhydrazine, urea, a lower alkyl amide, nitramine, a mono-substitutednitramine, and hydroxylamine.

17 4. The process which comprises (1) reacting a reagent selected fromthe group consisting of F NF wherein -X is selected from the groupconsisting of NF NF: -F, NF3, -NFNF, --NF--(%NF:, NFCEN,

and NF-NF:

when 2-- is F and wherein X is -NFCEN when Z- is NEO- and wherein Y isselected from the group consisting of with an additive selected from thegroup consisting of 18 HNCO, HNCS, and HgNC-EN to produce an adduct, and(2) reacting said adduct with a compound selected from the groupconsisting of aliphatic carboxylic, aromatic carboxylic, and water.

References Cited UNITED STATES PATENTS 2,963,468 12/ 1960 Cleaver26087.5 3,149,165 9/ 1964 Sausen 260-583 3,166,595 l/1965 Frazer 260583LELAND A. SEBASTIAN, Primary Examiner US. Cl. X.R.

14922, 36, 109; 260- 220, 453 AL, 454, 465.5 R, 479 C, 482 B, 482 C,513.5, 553 R, 553 A, 564 R, 564 B, 583 NH, 584 A I UNITED STATES PATENTOFFICE CERTIFICATE OF CORECTEON Patent No. 5,699,094 I Dated October 17,1972 Inventor William Charles Firth, Jr. and Simon Frank It is certifiedthat error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

Column 1, line 50, "avaliable" should read available Column 2, line 5,"NQQ )n should read NQQ )n v H H v Column 2, line 50, to the right ofthe formula "a (1" should read and Column 2, line 55, omit the word "thebefore results and after and. Column 4, line 57, "NH QNH' should readNll -NH Column 6, line 57, IV. X" should read XXIV Column '7, line 58, gshould read N]?! F a Column 7, line 6%, "perfluorodicyanoguanidlne"should read perfluorodicyanoguanidine Column '7, line70, "reactant-Vshould read reactant. Column 9, line 11, "proucing" should readproducing Column 10, line 5, "moditions" should read conditions Column10, line 24, "multiple" should read multiply Column 10, line '74, "NF

FNCF NF,

should read NF Column 11, line 45, NHF" I ENCE, NF

should read NHF Column 11, line 55 "OCH should I -II F N-C-F Y -o=s FORMPO-IOSO (10-69) USCOMM'DC 60376-P69 W 0.5 GOVIINNINT PRINTING OFFICEI969 0-360-334 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No. 5,699,094 bated October 17.. 1972 lnventofls) William CharlesFirth. Jri and Si Frank I Z It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrectedas shown below:

- a read OCH Column 11, line 65, "HNNNH should read -c=s O=C-NH I F-C-NFHNNH Column 12, line 10, "EN-0:0" should read I I O=C-NH N--CH 1 v NFZ oH1\ -C=O Column 14, line '46, "examples" should read 7 v T T- CH exampleColumn 14; line 69, "c mr o should read C H, F N 0 Column 15, line 4,"ractor" should read reactor Column 15, line 12, "whoe" should readwhose Column l5, line 55, "contradistriction" should readcontradistinction Column 16, line 55, "-NF-C=N, should read -l1F-C-:'1\T, Column 18, lines 5 and t, insert the word "acids" after theword carboXyl-ic" both times.

Signed and sealed this 1st day of May 1973.

(SEAL) Attest:

nowAno rnb'nuunnnn, JR. ROBERT GOTTSCHALK Attesting Officer 7Commissioner of Patents FORM PO-IOSO (10-69)

1. A COMPOUND HAVING A STRUCTURAL FORMULA
 2. THE PROCESS WHICH COMPRISES(1) REACTING A REAGENT SELECTED FROM THE GROUP CONSISTING OF